Aldehyde Dehydrogenase 2 (ALDH2) rs671 Polymorphism is a Predictor of Pulmonary Hypertension Due to Left Heart Disease.

AIM: Pulmonary hypertension due to left heart disease (PH-LHD) is commonly seen in patients with heart failure (HF), but there are limited treatment options. Recent studies have shown an association between aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphisms and pulmonary hypertension (PH). Therefore, this study aimed to investigate the occurrence of ALDH2 rs671 polymorphisms, and the association between ALDH2 and risk of PH-LHD in patients with HF. It also investigated different ALDH2 genotypes and examined their association with cardiac structure and function in HF patients with PH-LHD. METHODS: A total of 178 HF patients were consecutively enrolled in this study: 102 without PH-LHD and 76 with PH-LHD. Clinical data, parameters of echocardiography, and relevant biochemical indexes were recorded in both groups. Differences in data obtained between groups were compared, and the risk of variant ALDH2 polymorphisms with PH-LHD in HF patients was analysed using univariate and multivariate logistic regression. RESULTS: The prevalence of ALDH2 rs671 GA/AA polymorphisms (variant ALDH2) was 24 of 102 patients (23.53%) in the HF without PH-LHD group, and 32 of 76 patients (42.10%) in the HF with PH-LHD group, with a statistically significant difference. Univariate and multivariate logistical regression showed that variant ALDH2 is an independent risk factor for HF combined with PH-LHD. A higher proportion of patients with variant ALDH2 in the HF with PH-LHD group had a tricuspid regurgitation velocity >2.8 m/s, and they had higher values of peak early diastolic velocity of the mitral orifice/peak velocity of the early diastolic wave of the mitral orifice, maximum frequency shift of pulmonary valve flow, and pulmonary artery stiffness. CONCLUSIONS: Variant ALDH2 may be an independent risk factor for HF combined with PH-LHD. Variant ALDH2 may also be involved in pulmonary artery remodelling and is a potential new target for clinical treatment of PH-LHD.

Evaluation of pulmonary artery stiffness and right ventricle functions in polycythemia vera patients by transthoracic echocardiography.

INTRODUCTION: Polycythemia vera (PV) is known to be a subgroup of chronic myeloproliferative neoplasms and is recognized as a cause of pulmonary hypertension (PH). Pulmonary artery stiffness (PAS) is a relatively new noninvasive echocardiographic index developed to evaluate the structural features and functions of the pulmonary vascular bed. In this study, we aimed to evaluate right ventricular (RV) functions and PAS in PV patients and healthy controls. METHODS: A group of 65 consecutive PV patients and 40 healthy controls were included in the study. RV global longitudinal strain (RVGLS) and RV free wall longitudinal strain were (RVFwLS) evaluated using two-dimensional (2D) strain echocardiography. RV volume, systolic and diastolic functions were evaluated with three-dimensional (3D) echocardiography. PAS was calculated using the maximum frequency shift (MFS) and acceleration time of the pulmonary artery flow trace. RESULTS: PAS values were significantly higher in the PV group than in the control group (25.2 ± 5.2 vs. 18.2 ± 4.2, p < .001). We found that tricuspid annular plane systolic excursion (TAPSE) (p < .001), RV fractional area change (p < .001) and RV ejection fraction (p < .001) measurements evaluated by 3D echocardiography were significantly lower in the PV group. CONCLUSION: In our study, PAS values were higher in PV patients than in the healthy control group. Patients with PV may have subclinical RV dysfunction, and PAS value can be used in the early diagnosis of PH and RV dysfunction in this patient group.

The relationship between bioelectrical impedance parameters and pulmonary artery stiffness in obese subjects.

OBJECTIVES: Obesity is a public health problem that needs to be treated and it occurs as a result of excessive fat accumulation in the body. The relationship between obesity and pulmonary hypertension is well known. The aim of this study is to evaluate the relationship between pulmonary artery stiffness, right ventricular functions and bioelectrical impedance parameters in obese, overweight, and healthy individuals. METHODS: In this study, 41 obese (17 female and 24 male, mean age 43.5±10.3), 39 overweight (20 female and 19 male, mean age 38.6±10.4), 34 healthy control group (19 female and 15 male, mean age 40.5±8.6) were included. Anthropometric measurements and bioelectrical impedance parameters of all participants were performed. Right ventricular functions and pulmonary artery stiffness were evaluated by using conventional echocardiography. RESULTS: Right ventricle myocardial performance index, pulmonary artery stiffness values were statistically different between groups. Positive correlation was observed between pulmonary artery stiffness and Body Mass Index, Waist and Hip circumferences. Significant negative correlation was observed between muscle to fat ratio and pulmonary artery stiffness. In the linear regression analysis, it was observed that the muscle to fat ratio was independent predictor of pulmonary artery stiffness (ß = -1.835; 95%CI(-2.434 - - .784); p < 0.001). CONCLUSIONS: This study showed that right ventricular function was impaired and pulmonary artery stiffness increased in obese individuals. These findings could be considered as early markers of pulmonary hypertension in obese patients who do not yet have clinical evidence of cardiovascular disease.

Assessment of pulmonary arterial stiffness in patients with cirrhosis: A prospective cohort study.

INTRODUCTION: In the current literature, several studies show that PAS (pulmonary artery stiffness) is associated with RV (right ventricular) dysfunction, PAH (pulmonary arterial hypertension), and disease severity in subjects with structural cardiac disease, HIV (human immunodeficiency virus), and chronic lung disease. Hence, our main aim was to use PAS to show the early changes in the pulmonary vascular region in subjects with cirrhosis. MATERIAL AND METHODS: In this prospective cross-sectional study, 39 subjects who were being followed up with cirrhosis and 41 age- and sex-matched healthy subjects were included in this study. For each case, the PAS value was obtained by dividing mean peak velocity of the pulmonary flow by the PfAT (pulmonary flow acceleration time). RESULTS: The measured PAS was 23.62 ± 5.87 (Hz/msn) in cirrhotic participants and 19.09 ± 4.16 (Hz/msn) in healthy cases (P < .001). We found a positive statistical significance between PAS and RVSP (right ventricle systolic pressure)/sPAP (systolic pulmonary arterial pressure) (r = .395; P = .013). PAS was an independent predictor that was associated with cirrhosis disease according to multivariate LR (logistic regression) analysis (OR: 1.209; 95% CI: 1.059-1.381; P = .005). CONCLUSION: Based on the study results, we consider that PAS may help in the early detection of findings in the pulmonary vascular area, even if the RV function findings or sPAP is within the normal range.

Evaluation of pulmonary artery stiffness in newly diagnosed adult patients with asthma.

BACKGROUND: There are limited studies on the effects of asthma on cardiac function. Right ventricular dysfunction and pulmonary hypertension are cardiovascular complications that may be seen in advanced stages of the disease. Pulmonary artery stiffness (PAS), is a promising, relatively new echocardiographic index that has been reported to increase in right ventricular failure, providing information about pulmonary vascular bed. AIM: In this study, we aimed to evaluate PAS, a marker of pulmonary artery elasticity, in adult-onset asthma. METHODS: Ninety-nine nonsmokers who had a new asthma diagnosis between the ages of 18 and 65 years and 97 healthy controls with similar age and sex distribution were included in the study. PAS was calculated by dividing the maximal frequency shift of pulmonary flow (MFS) in pulmonary acceleration time (PAT). RESULTS: Clinical and demographic characteristics of both groups were similar (P Ëƒ 0.05). PAS values were higher in the asthma group than in the control group (25.2 ± 4.5 vs 22.4 ± 4.1, P ˂0.001). TAPSE was lower in the case group (24.9 ± 2.0 vs 25.5 ± 2.1, P = 0.043), while RV MPI was higher (0.36 ± 0.07 vs 0.32 ± 0.06, P ˂0.001). In the multivariate linear regression analysis, RV MPI, RV Em, and TAPSE variables were independent predictors of PAS. CONCLUSION: In our study, PAS values were higher in patients with newly diagnosed adult asthma and we found a significant weak correlation between PAS values and subclinical right ventricular dysfunction.

Evaluation of Pulmonary Artery Stiffness in Patients with Obstructive Sleep Apnea Syndrome.

OBJECTIVE: To investigate whether obstructive sleep apnea syndrome (OSAS) has any effect on pulmonary artery stiffness (PAS) derived from echocardiographic calculation. METHODS: Fifty-two patients with newly diagnosed OSAS and forty-two subjects without OSAS matched by age and sex were enrolled in the study. OSAS was categorized according to apnea hypopnea index (AHI, event/h) as follows: normal (AHI<5), mild OSAS (AHI 5-15), moderate and severe OSAS (AHI>15). All participants were evaluated by echocardiography to determine PAS and right ventricle functions. PAS was calculated throughout pulmonary artery flow by the formula; PAS (kHz/sec) = maximal frequency shift/acceleration time. RESULTS: Demographic and clinical parameters were similar in both groups. PAS significantly increased in OSAS compared with the control group (26.9 ± 6.1 vs. 18.0 ± 3.5, P < 0.001). Additionally, PAS in severe and moderate OSAS was considerably high compared with that in mild OSAS and control group (P < 0.001). Right ventricular myocardial performance index (MPI) and mean pulmonary artery pressures (mPAP) were considerably higher in OSAS group than control group (P < 0.001). Tricuspid E/A, right ventricle tissue Doppler E'/A', and right ventricular ejection time (RVET) decreased in OSAS group compared with control group (P < 0.001). There was a significantly positive correlation between PAS and AHI, mPAP, and MPI (P < 0.001), and a significantly negative correlation between PAS and tricuspid E/A, E'/A', and RVET (P < 0.001). Linear regression analyses showed that PAS was an independent factor for mPAP (ß = 0.595, P = 0.034). CONCLUSION: Elastic properties of pulmonary artery deteriorate with severity of OSAS and may be responsible for right ventricular dysfunctions in OSAS.

Elasticity properties of pulmonary artery in patients with bicuspid aortic valve.

OBJECTIVE: Although the vascular complications of bicuspid aortic valve (BAV) disease cause significant morbidity and mortality, the role of pulmonary artery in this pathogenesis is less understood. We aimed to assess the elastic properties of pulmonary artery with echocardiography in patients with BAV. MATERIAL AND METHODS: Thirty patients with BAV (26 males) were enrolled in this study. The presence of aortic stenosis was accepted as exclusion criteria. Thirty-two healthy subjects (27 males) with no any history of cardiovascular disease comprised the control group. In all patients, maximal frequency shift (MFS) and acceleration time (AcT) of the pulmonary artery flow trace were measured echocardiographically in parasternal short-axis view. Subsequently, pulmonary artery stiffness (PAS) was calculated by using the following formula PAS (kHz/sec) = MFS/AcT. RESULTS: There were no significant differences in baseline demographic characteristics of the study population. Aortic strain and aortic distensibility index were lower, and aortic stiffness index (SI) higher, in patients with BAV. The PAS was significantly increased in patients with BAV compared with control subjects with tricuspid aortic valve (11.08 ± 2.27 vs. 7.11 ± 1.54, P < 0.001). There was a significant correlation between aortic diameters, aortic elasticity indexes, and PAS. Multivariate linear regression analysis, the only significant independent factor affecting the PAS was SI (ß = 0.547, P < 0.001). CONCLUSION: We demonstrated that elastic properties of pulmonary artery tend to be impaired as in the aorta in patients with BAV disease.

Evaluation of pulmonary arterial stiffness in post mild COVID-19 patients: a pilot prospective study.

BACKGROUND: Our primary goal was to utilize pulmonary arterial stiffness (PAS) to demonstrate the early alterations in the pulmonary vascular area in individuals with prior COVID-19 illness who had not undergone hospitalization. METHODS: In total, 201 patients with prior COVID-19 infection without hospitalization and 195 healthy, age- and sex-matched individuals without a history of COVID-19 disease were included in this prospective analysis. The PAS value for each patient was calculated by dividing the mean peak pulmonary flow velocity by the pulmonary flow acceleration time. RESULTS: The measured PAS was 10.2 ± 4.11 Hz/msec in post-COVID-19 participants and 8.56 ± 1.47 Hz/msec in healthy subjects (P < 0.001). Moreover, pulmonary artery acceleration time was significantly lower in patients with a prior history of COVID-19. Multivariable logistic regression analysis revealed that PAS was significantly connected to a prior COVID-19 illness (odds ratio, 1.267; 95% confidence interval, 1.142-1.434; P < 0.001). The optimal cutoff point for detecting a prior COVID-19 disease for PAS was 10.1 (sensitivity, 70.2%; specificity, 87.7%). CONCLUSIONS: This might be the first investigation to reveal that patients with a history of COVID-19 had higher PAS values compared to those without COVID-19. The results of the investigation may indicate the need of regular follow up of COVID-19 patients for the development of pulmonary arterial hypertension, especially during the post-COVID-19 interval.

Fetal pulmonary artery stiffness is a strong predictor of persistent pulmonary hypertension of the newborn - An echocardiographic study.

OBJECTIVE: Pulmonary artery stiffness (PAS) is a strong and independent predictor of mortality in adult patients with pulmonary hypertension (PH). But the change in PAS during perinatal period remains unknown. Here, we aimed to explore the feasibility and performance of PAS on predicting persistent pulmonary hypertension of the newborn (PPHN). METHODS: 1325 fetuses underwent a dedicated echocardiography screening for fetal heart defects during second trimester, third-trimester and neonatal period with the measurement of acceleration time (PAAT) and maximal frequency shift (MFS) of pulmonary artery flow. PAS (MFS/PAAT ratio) was calculated. RESULTS: Six fetuses were diagnosed as PPHN. Compared with the normal fetuses, those with PH had greater values of PAS during each period of time (second trimester, 52.6(46.2-54.5) vs. 32.4(28.0-39.4) kHz/s, p = 0.0003; third trimester, 52.9(46.1-55.3) vs. 29.7(27.3-33.3) kHz/s, p = 0.0002; neonatal period, 127.4(85.2-150.8) vs. 26.6(22.7-35.0) kHz/s, p < 0.0001). There was a statistically significant correlation between PAS and mean pulmonary artery pressure (p < 0.05) but no correlation between PAS and gestational age (p > 0.05) whether in normal fetuses or not. The area under receiver operating characteristic curve (AUC) of 0.97 for PAS during third trimester was superior to that for PAS during second trimester (AUC, 0.94) in predicting PPHN. The optimal cutoff value of PAS during third trimester was 37.40 KHz/s, with a sensitivity of 100%, a specificity of 91%, and an accuracy of 92%. CONCLUSION: There was a significant difference in PAS between normal fetuses and those with PH. PAS has a power performance on predicting PPHN.

Assessment of pulmonary artery stiffness by multiparametric cardiac magnetic resonance-surrogate for right heart catheterization.

Background: Cardiac magnetic resonance (CMR) imaging allows for multiparametric assessment of healthy pulmonary artery (PA) hemodynamics. Gender- and aging-associated PA stiffness and pressure alterations have remained clinically unestablished, however may demonstrate epidemiological differences in disease development. The aim of this study is to evaluate the role of CMR as a surrogate for catheter examinations by providing a comprehensive CMR assessment of sex- and age-related reference values for PA stiffness, flow, and pressure. Methods and Results: PA hemodynamics were studied between gender and age groups (>/<50 years) using phase-contrast CMR. Corresponding correlation analyses were performed. 179 healthy volunteers with a median age of 32.6 years (range 11.3-68.2) were examined. Males demonstrated increased PA compliance (median [interquartile range] or mean ± standard deviation) (20.8 mm2/mmHg [16.6; 25.8] vs. 19.2 ± 7.1 mm2/mmHg; P < 0.033), higher pulse wave velocity (2.00 m/s [1.35; 2.87] vs. 1.73 m/s [1.19; 2.34]; P = 0.018) and a reduced full width half maximum (FWHM) (219 ± 22 ms vs. 235 ± 23 ms; P < 0.001) than females. Mean, systolic, diastolic PA pressure and pulmonary proportional pulse pressure were significantly elevated for males compared to females (P < 0.001). Older subjects (>50 years) exhibited reduced PA elasticity (41.7% [31.0; 52.9] vs. 66.4% [47.7; 83.0]; P < 0.001), reduced PA compliance (15.4 mm2/mmHg [12.3; 20.7] vs. 21.3 ± 6.8 mm2/mmHg; P < 0.001), higher pulse wave velocity (2.59 m/s [1.57; 3.59] vs. 1.76 m/s [1.24; 2.34]; P < 0.001) and a reduced FWHM (218 ± 29 ms vs. 231 ± 21 ms; P < 0.001) than younger subjects. Conclusions: Velocity-time profiles are dependent on age and gender. PA stiffness indices deteriorate with age. CMR has potential to serve as a surrogate for right heart catheterization.

Impact of pulmonary artery stiffness on right ventricular function and tricuspid regurgitation after successful percutaneous balloon mitral valvuloplasty: the importance of early intervention.

AIMS: We assessed impact of pulmonary artery stiffness (PAS) on the long-term right ventricular (RV) function and tricuspid regurgitation (TR) changes after percutaneous balloon mitral valvuloplasty (PBMV). METHODS AND RESULTS: Using Doppler echocardiography, PAS was calculated by dividing maximal frequency shift of pulmonary flow by the acceleration time, and mitral area, RV function, and degree of TR severity were evaluated before, immediately after, 6 months, and 12 months after successful PBMV in 81 consecutive patients. Compared with control subjects patients with mitral stenosis (MS) had significant higher PAS (P < 0.001). The PAS was significantly lower in patients with progressive RV function improvement and regression of TR (P < 0.001). PAS was significantly correlated with the degree of pulmonary artery systolic pressure (PASP), tricuspid annular plane systolic excursion (TAPSE), and E/E'm ratio (P < 0.0001, <0.0001, and < 0.001, respectively). Multivariate regression analysis showed that the PAS is an independent predictor of TR regression and sustained RV functional improvement after successful PBMV (P < 0.0001). CONCLUSIONS: The changes in RV function and TR after successful PBMV were significantly correlated with the degree of PAS. Despite a sustained increase in mitral valve area, some patients showed no regression of TR, and progressive RV dysfunction suggests a significant role of PAS on RV function and the degree of TR regression in patients with MS suggests that PBMV must be performed early, utilizing PAS as a noninvasive parameter for proper timing for PBMV.

Feasibility of Echocardiographic Estimation of Pulmonary Artery Stiffness in Horses.

Pulmonary artery stiffness (PAS) is an index of pulmonary artery elasticity that permits to evaluate the pulmonary vascular bed in humans. It can early detect an increase in pulmonary artery stiffness as a consequence of remodeling of the vessel wall caused by chronic pulmonary and congenital heart diseases. This remodeling can occur also in horses with chronic respiratory diseases. Thus, PAS could be a useful echocardiographic parameter also in horses. However, in literature, there are no studies regarding PAS in horses. The aim of this study is to evaluate the feasibility of PAS in horses. Fifteen healthy horses were included in this prospective study. Maximal frequency shift and acceleration time were measured from the pulsed-wave Doppler trace of the pulmonary artery flow, obtained from the right parasternal short-axis view at the level of the pulmonary artery, and then PAS was calculated as the ratio of Maximal frequency shift to acceleration time. The low variability assessed for intra- and inter-observer variability, day-to-day variability and image acquisition variability suggests that PAS can be measured consistently in horses. Further studies could be useful to assess the clinical usefulness of PAS in unhealthy horses, such as those affected by chronic respiratory diseases.

Effects of angiotensin receptor neprilysin inhibition on pulmonary arterial stiffness in heart failure with reduced ejection fraction.

The sacubitril/valsartan combination is an important agent used in the treatment of heart failure with reduced ejection fraction (HFrEF). Pulmonary artery stiffness (PAS) is an index developed to evaluate the pulmonary vascular bed. Changes in pulmonary vascular structures in HFrEF patients can affect PAS. In this study, we aimed to investigate the effect of sacubitril/valsartan on PAS in HFrEF patients. One hundred fifty HFrEF patients, who received sacubitril/valsartan therapy and continued for at least 6 months without interruption, were examined retrospectively. N-terminal pro-B-type natriuretic peptide levels (NT-proBNP), NYHA classes, Minnesota Living with Heart Failure Questionnaire (MLWHFQ) scores, New York Heart Association (NYHA) functional classes and echocardiograpic parameters such as left ventricular ejection fraction (LVEF), mean pulmonary artery pressure (mPAP), right ventricle myocardial performance index (RV-MPI), Tricuspid annular plane systolic excursion (TAPSE), right ventricular fractional area change (RV-FAC) and PAS changes were evaluated before and 6 months after sacubitril/valsartan treatment. PAS was calculated by using the maximal frequency shift and acceleration time of the pulmonary artery flow trace measured in the echocardiogram. PAS values were significantly reduced (23.8 ± 2.8 vs 19.1 ± 3.1 kHz/ms, p < 0.001) after the sacubitril/valsartan treatment. Sacubitril/valsartan treatment was associated with significant improvements in NYHA class and MLWHFQ scores; significant reductions in the NT-proBNP levels, mPAP, and RV-MPI, and significant increases in LVEF, TAPSE, and RV-FAC (p < 0.05). The significant reduction in the PAS value was significantly correlated with the improvements in the MLWFQ scores, NT-proBNP levels, mPAP, RV-MPI, TAPSE and RV-FAC. In HFrEF patients, switching from angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker therapy to sacubitril/valsartan may result in reduction in PAS.

Novel Noninvasive Assessment of Pulmonary Arterial Stiffness Using Velocity Transfer Function.

Background Pulmonary artery ( PA ) stiffness is associated with increased pulmonary vascular resistance ( PVR ). PA stiffness is accurately described by invasive PA impedance because it considers pulsatile blood flow through elastic PA s. We hypothesized that PA stiffness and impedance could be evaluated noninvasively by PA velocity transfer function ( VTF ), calculated as a ratio of the frequency spectra of output/input mean velocity profiles in PA s. Methods and Results In 20 participants (55±19 years, 14 women) undergoing clinically indicated right-sided heart catheterization, comprehensive phase-contrast and cine-cardiac magnetic resonance imaging was performed to calculate PA VTF , along with right ventricular mass and function. PA impedance was measured as a ratio of frequency spectra of invasive PA pressure and echocardiographically derived PA flow waveforms. Mean PA pressure was 29.5±13.6 mm Hg, and PVR was 3.5±2.8 Wood units. A mixed-effects model showed VTF was significantly associated with PA impedance independent of elevation in pulmonary capillary wedge pressure ( P=0.005). The mean of higher frequency moduli of VTF correlated with PVR (ρ=0.63; P=0.003) and discriminated subjects with low (n=10) versus elevated PVR (≥2.5 Wood units, n=10), with an area under the curve of 0.95, similar to discrimination by impedance (area under the curve=0.93). VTF had a strong inverse association with right ventricular ejection fraction (ρ=-0.73; P<0.001) and a significant positive correlation with right ventricular mass index (ρ=0.51; P=0.02). Conclusions VTF , a novel right ventricular- PA axis coupling parameter, is a surrogate for PA impedance with the potential to assess PA stiffness and elevation in PVR noninvasively and reliably using cardiac magnetic resonance imaging.

Both Systemic and Pulmonary Artery Stiffness Predict Ventricular Functional Recovery after Successful Percutaneous Closure of Atrial Septal Defects in Adults.

BACKGROUND: Percutaneous closure of atrial septal defect (ASD) has become the preferred method in treatment of the majority of cases. The aim of this study was to evaluate the echocardiographic effects of percutaneous closure of secundum ASD in adults and assess which parameters predict good response to closure. DESIGN: We prospectively included 42 patients with secundum ASD treated successfully with percutaneous device closure. All patients underwent transthoracic echocardiography examination with tissue Doppler imaging before, 24 hours after and within 3 months of intervention. Measurements of arterial stiffness were carried out using a Mobil-O-Graph arteriography system. RESULTS: Remodeling of heart chambers occurred immediately and persisted at 3 months after ASD closure. Significant decreases were observed in right ventricle (RV) end-diastolic diameter, right atrium volume index, and tricuspid annular plane systolic excursion both after the procedure and at 3 months (P < .01 for all). The RV and left ventricle (LV) tissue Doppler-myocardial performance index demonstrated to decline during follow up (P = .0001). Significant correlations were found between pulse-wave velocity, augmentation index, pulmonary artery stiffness, and LV-RV tissue Doppler-myocardial performance index at third month. Linear regression analyses showed that pulse-wave velocity is the most effective parameter of LV and pulmonary artery stiffness is the most effective parameter of RV functional recovery, respectively, assessed by tissue Doppler-myocardial performance index. CONCLUSIONS: Percutaneous closure of secundum ASD in adults has various sustained benefits on multiple echocardiographic parameters within 3 months. The changes in RV and LV function after device closure were significantly correlated with the degree of pulmonary artery stiffness and pulse-wave velocity, respectively.

Hemodynamic assessment of pulmonary hypertension.

There has been significant progress in our understanding of the pathobiology, epidemiology and prognosis of pulmonary vascular disease and, over the past few years, there has been an explosion of clinical therapeutic trials for pulmonary arterial hypertension (PAH). The increasing number of different conditions now associated with PAH and the appearance of new diagnostic techniques have led to a need for a systematic diagnostic approaches and a new disease classification, which has resulted in notable improvements in the quality and efficacy of clinical care. We appreciate traditional resting right heart catheterization techniques (which still remain the gold standard for diagnosing PAH and managing patients on therapy) and look forward to novel invasive techniques (e.g. intravascular ultrasound) that add greatly to our understanding of right ventricle and pulmonary circulation, and for the interpretation of data from clinical trials as well.